UNFAIR BILLING

I received notification to upgrade my WiFi contract on 11 May 2024. On 11 May I went to MTN at The Grove to upgrade. I was told I can only upgrade on 11 July. On 11 July I couldn't upgrade as I was on the road for work. I upgraded telephonically on 12 July. Got an allocated billing of R1198.85 because I failed to upgrade on 11 July. I am being charged this amount because I missed the renewal of my contract by one day. I don't think it is fair to charge a client because they couldn't upgrade immediately. What if the 11th was on a Sunday? I will not pay this money. MTN should have told me then to make sure I upgrade on the exact date.